In my day dissecting frogs was the pinnacle of high school biology. A generation later students could make glowing frogs. In 2030 school children will be designing and growing eight foot tall giant ants for the stage version of Them. (Yes, feet, the U.S. will stand alone as metric deniers.)

ZAZ:In my day dissecting frogs was the pinnacle of high school biology. A generation later students could make glowing frogs. In 2030 school children will be designing and growing eight foot tall giant ants for the stage version of Them. (Yes, feet, the U.S. will stand alone as metric deniers.)

in my day... the frog was the lead up to the pig fetus... which some of us jackasses in class used the small intestine as a jump rope... I wanna say this was about... 1991-2?

thatboyoverthere:To be specific the cube-square law in relation to their trachea. They get too big and the trachea can not take in enough oxygen to keep up cellular respiration./Thank God.

Basically, 1: Their legs would not be strong enough to hold their weight. 2: Those with wings certainly would not be able to fly, and 3: their lungs would not be big enough to service their now giant bodies.

Here's something fun to consider. If we ever have space stations, or build outposts on lower gravity planets we will no doubt bring some common pests along with us. We always do. Rats? Cockroaches? These critters breed fast, and in lower gravity they can grow MUCH MUCH larger...

Exterminators will need body armor. And you wouldn't want to meet a roach on your way to the fridge, or on its way to your fridge.

ZAZ:In my day dissecting frogs was the pinnacle of high school biology. A generation later students could make glowing frogs. In 2030 school children will be designing and growing eight foot tall giant ants for the stage version of Them. (Yes, feet, the U.S. will stand alone as metric deniers.)

tinyarena:Here's something fun to consider. If we ever have space stations, or build outposts on lower gravity planets we will no doubt bring some common pests along with us. We always do. Rats? Cockroaches? These critters breed fast, and in lower gravity they can grow MUCH MUCH larger...Exterminators will need body armor. And you wouldn't want to meet a roach on your way to the fridge, or on its way to your fridge.Remember clockspider? Pleasant dreams y'all

Of course, the question is why didn't insects just evolve a way around it. Moving past tracheal passages and developing lungs or some other mechanism to get more oxygen from the air.The only solution I can think of is the arrival of vertebrates and their higher intelligence.A larger insect has longer periods of vulnerability when it molts, and with vertebrates around there isn't much room for insects to evolve size wise.